/* 重置样式 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, 
    Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  line-height: 1.5;
  background-color: #f5f5f5;
}

a {
  color: inherit;
  text-decoration: none;
}

/* 响应式图片 */
img {
  max-width: 100%;
  height: auto;
  vertical-align: middle;
}